McCarthy M M, McDonald C H, Brooks P J, Goldman D
Department of Physiology, University of Maryland School of Medicine, Baltimore 21201, USA.
Physiol Behav. 1996 Nov;60(5):1209-15. doi: 10.1016/s0031-9384(96)00212-0.
The established role of oxytocin (OT) in facilitation of steroid-modulated reproductive and affiliative behaviors led to the speculation that it may have anxiolytic actions under certain hormonal conditions. NIH-Swiss mice were tested for responsiveness to OT in two behavioral tests of anxiety, the holeboard apparatus and elevated plus-maze. Dose-response assessment indicated that 3 mg/kg was the optimal dose for peripherally administered (IP) OT on the elevated plus-maze. There were no consistent effects at any dose on the holeboard apparatus. In ovariectomized mice pretreated with estradiol (E2), peripherally administered OT increased the number of entrances onto the open arms, as well as the amount of time on the open arms compared to other groups (ANOVA; p < 0.05). There was little to no effect of OT in ovariectomized animals not pretreated with E2. When OT was administered intracerebroventricularly (ICV), there was an increase in entrances and time on the open arms compared to that of females infused with arginine vasopressin (AVP). This increase was apparent in ovariectomized females, but was further enhanced in those pretreated with E2 (ANOVA; p < 0.05). In contrast, the combination of E2 pretreatment and ICV AVP decreased the number of entrances and time spent on the open arms of the elevated plus-maze compared to those receiving OT, suggesting an estrogen-modulated anxiogenic action of AVP. Analyses of [125]I-OVTA binding density indicated a significant increase in binding density in the lateral septum of E2-treated females compared to OIL-treated controls (ANOVA; p < 0.05). There was no effect of E2 treatment on [125]I-OVTA binding density in the amygdala or ventromedial nucleus of the hypothalamus. Taken together, these data indicate that OT exerts an anxiolytic action that is enhanced in the presence of circulating estrogen. This behavioral effect may be mediated by estrogen-induced increases in OT binding density in the lateral septum and may be important to the facilitation of social interactions.
催产素（OT）在促进类固醇调节的生殖和亲和行为方面已确立的作用引发了这样的推测：在某些激素条件下它可能具有抗焦虑作用。在两项焦虑行为测试——洞板实验和高架十字迷宫实验中，对NIH-瑞士小鼠进行了OT反应性测试。剂量反应评估表明，3mg/kg是外周注射（腹腔注射）OT用于高架十字迷宫实验的最佳剂量。在洞板实验中，任何剂量下均未观察到一致的效果。在经雌二醇（E2）预处理的去卵巢小鼠中，与其他组相比，外周注射OT增加了进入开放臂的次数以及在开放臂上停留的时间（方差分析；p<0.05）。在未用E2预处理的去卵巢动物中，OT几乎没有影响。当脑室内注射（ICV）OT时，与注射精氨酸加压素（AVP）的雌性小鼠相比，进入开放臂的次数和在开放臂上停留的时间增加。这种增加在去卵巢雌性小鼠中很明显，但在用E2预处理的小鼠中进一步增强（方差分析；p<0.05）。相反，与接受OT的小鼠相比，E2预处理和ICV AVP的组合减少了高架十字迷宫开放臂上的进入次数和停留时间，表明AVP具有雌激素调节的致焦虑作用。对[125]I-OVTA结合密度的分析表明，与用油性对照处理的小鼠相比，经E2处理的雌性小鼠外侧隔区的结合密度显著增加（方差分析；p<0.05）。E2处理对杏仁核或下丘脑腹内侧核的[125]I-OVTA结合密度没有影响。综上所述，这些数据表明OT具有抗焦虑作用，在循环雌激素存在时这种作用会增强。这种行为效应可能是由雌激素诱导的外侧隔区OT结合密度增加介导的，并且可能对促进社交互动很重要。
